This invention relates to a machine intended for automatically positioning and continuously feeding containers, for example bottles or other hollow articles made from synthetic material, which may be of very different sizes and shapes. This machine is designed for continuous feeding of other machines such as high production filling machines or similar equipment and is able to carry out this function owing to the large number of containers which it can position correctly and feed per unit of time.
Known machines of the type to which the present invention relates include in general:
a) a hopper of any shape or dimension provided with an opening to receive in bulk containers that fall onto a bottom plane whose edges are at a distance from the side wall of the hopper providing a peripheral space allowing the passage of the containers;
b) a structure provided with displacement means in an enclosed circuit, located below the bottom plane, including, fully or in part:
a plurality of detachable container holding elements removably mounted at the periphery of the structure defining a series of recesses adapted to receive containers in a lying position and provided with retaining means for one part of the containers, namely their neck, in such a way as to release them in a predetermined position, usually with the neck upward;
a plurality of discharge chutes provided under the recesses for receiving and transferring the containers, correctly oriented, towards an exit conveyor that feeds, for example, a bottling line;
c) a plane or shelf, which may be adjustable in height, located below the recesses and over the chutes, designed to support the containers when they are conveyed by the holding elements defining the recesses for receiving and retaining them in a lying position, the plane or shelf being provided with an opening in an unloading area through which the containers drop when moved into position thereover by the container holding elements.
Machines known to the applicant are the following grouped by the function they perform:
a) Aidlin machine (U.S. Pat. No. 3,295,659) relates to a machine comprising a hopper into which the containers or bottles which are to be sorted are randomly loaded, having an inclined axis, an inclined disc constituting the bottom of the hopper and adapted to rotate about the inclined axis, a plurality of openings at the periphery of the disc each adapted to receive and pass one container while retaining the neck which is supported on the disc for transporting them from a receiving zone to an unloading zone, associated with a fixed plate beneath and parallel to the rotatable disc providing a support for the container bodies during their rotation and having a release opening in an upper part of the plate aligned with the path of movement of the containers as the disc rotates, so that the containers fall, by gravity, one by one in an upright position into a fixed chute or guideway located below the opening;
Australian patent AU 499,038 (HOEHN) discloses the basic technical feature which facilitates carrying out the function of aligning the containers, previously oriented in upright position in the same machine, according to a principle similar to that disclosed in the above U.S. Pat. No. 3,295,659, from a plurality of falling chutes into which the containers fall, in an upright position, arranged under each of the openings, which are made from annular and radial elements located on the periphery of a rotary disc, rotating at the same speed as the openings and associated with a fixed support and a recovery conveyor.
The bottom of the machine and/or the rotatable disc or plane having the openings, is, in general, inclined, though it can be constructed in the shape of a cone or frustum of a cone having a vertical axis, as this solution can be found in the state-of-the-art, and it appears disclosed, for example, in German Patent DE 277347 (Polte) and U.S. Pat. No. 1,823,995 (Streby), which refers to machines of the same type as described above, in which case the inclined plane of the rotary element will by its slope and at the periphery move the containers upwardly defining a guiding duct which promotes the passage of the containers toward the openings associated with the falling chutes. The bottom plane, according to the above background prior art, is provided with a rotation movement in the same or opposite sense to the openings for collecting and conveying the containers.
On the other hand, the problem for adapting a machine of this type to different container shapes and sizes (length and cross section or thickness) has been overcome in several ways. Set forth below are the most relevant patents relating to this aspect:
British Patent GB 1,558,379 (Hoehn) which refers to a machine as disclosed in patent AU 499,038, of the same applicant, in which means have been devised to adjust the gap between the internal and the external walls and/or between the end walls of each opening to collect and hold the containers, and to adapt the space of the openings to the container size and shape. This means comprises plates with slides which provide a displacement allowing to adapt the passageway of the opening, and which are locked to bolts by nuts;
German Patent (corresponding to U.S. Pat. No. 4,130,194) DE 26 51 495 (Rationator) which refers to a machine similar to that disclosed in Australian Patent AU 499,038, wherein the openings are pierced on the edge of the disc, open at the exterior, and whose edge is formed by a series of continuous, annular, peripheral, exchangeable segments fixed to the periphery of the rotatable disc;
U.S. Pat. No. 4,681,209 (to be same applicant MARTI) which relates to a machine similar to that disclosed in Australian Patent AU 499,038, but wherein the openings are formed by radial, peripheral, detachable and exchangeable parts, which define the areas to house the containers as delimited between their sides, the edge of a rotatable disc and the hopper wall.
However, none of the above machines is completely satisfactory with regard to the adaptability of the machine to several sizes and/or forms of the containers, or the conditions in which the containers are conveyed. These prior machines have the drawbacks pointed out below.
The machines disclosed in the Australian Patent AU 499,038 and the British Patent GB 1,558, 379 require individual parts associated with each opening being adjusted, which means a delicate adjustment which must be carried out by skilled personnel; there exists the risk that some mismatching or position-related impairment of some of the parts occur due to impacts caused by clogging of the containers during their movement; summarizing, these machines require handling a great number of complex components with consequent labor cost.
The machine of German Patent DE 26 51 495, requires some continuous annular segments to be changed, and therefore has the following drawbacks:
the use of mechanized parts of a certain length and, therefore, of a limited modularity, different for each form of container;
locking the segments to the periphery of the disc with screws, which requires a delicate and time consuming handling at the installation point, and which, in general, demands an access structure to be provided at the top, within the machine, and/or the use of lifting means for removing the segments;
friction with the periphery of the receptacle, as the openings are outwardly open, which can produce damage to the containers (namely, bearing in mind the thin thickness of the wall, in a number of cases) as well as breaking during their access to the openings and in the area of falling downward into the evacuation ducts;
The machine of U.S. Pat. No. 4,681,209 has a risk similar to the above mentioned for the Australian and British patents, (HOEHN) that mismatching or impairments of the position devised for the unit radial parts, by accidental causes, and as the openings are outwardly open damages can likewise be produced to the containers, as well as problems of breaking upon access of the containers within the opening and the unloading area.
Of course, a machine of the type disclosed in U.S. Pat. No. 3,295,659 would require, for its adaptation to different forms of containers, changing the whole disc provided with openings with the consequent cost and labor for its execution.
It must be pointed out, in addition, that conveying containers in openings provided in a rotary element such as a disc, requires, for a drive stability, a significant thickness of the disc which allows it to encompass, at least, a significant part of the thicker part of the containers as it appears in the above U.S. Pat. No. 3,295,659, with subsequent production cost, weight and power consumption. In addition, in general, a part of the container always remains on the top and another under the transport element formed by the openings which produces a resistance to forward movement because of the atmosphere within the machine which can affect the positioning stability of slight containers such as plastic bottles treated in these machines, namely, at high speeds of the transport element.